Jensen M, Bunn H F, Halikas G, Kan Y W, Nathan D G
J Clin Invest. 1973 Oct;52(10):2542-7. doi: 10.1172/JCI107445.
Cyanate and 2,3-diphosphoglycerate (2,3-DPG) both influence the oxygen affinity of hemoglobin. The studies presented here concern the effects of these compounds on the sickling phenomenon. The inhibitory effect of cyanate on sickling is largely due to the fact that it increases the percentage of oxyhemoglobin S at a given oxygen tension. In addition, cyanate inhibits sickling by a mechanism that is independent of oxygenation. In this paper, we have demonstrated that the viscosity of carbamylated sickle blood was lower than that of non-carbamylated controls at the same oxygen saturation. Furthermore, carbamylation resulted in an increase in the minimum concentration of deoxy-sickle hemoglobin required for gelation. Like cyanate, 2,3-DPG affected sickling of intact erythrocytes by two mechanisms. Since 2,3-DPG decreases the percentage of oxyhemoglobin S at a given oxygen tension, sickling is enhanced. In addition, 2,3-DPG had a direct effect. When the intracellular 2,3-DPG concentration was increased in vitro, a greater percentage of cells were sickled at a given oxygen saturation. Conversely, sickling was inhibited in cells in which 2,3-DPG was artificially lowered. These data indicate that the enhancement of sickling by 2,3-DPG is in part independent of its influence on oxygen affinity.
氰酸盐和2,3 -二磷酸甘油酸（2,3-DPG）都会影响血红蛋白的氧亲和力。本文所呈现的研究关注这些化合物对镰状化现象的影响。氰酸盐对镰状化的抑制作用很大程度上是因为在给定的氧张力下它会增加氧合血红蛋白S的百分比。此外，氰酸盐通过一种与氧合作用无关的机制抑制镰状化。在本文中，我们已经证明，在相同的氧饱和度下，氨甲酰化镰状细胞血液的黏度低于未氨甲酰化的对照血液。此外，氨甲酰化导致凝胶化所需的脱氧镰状血红蛋白的最低浓度增加。与氰酸盐一样，2,3-DPG通过两种机制影响完整红细胞的镰状化。由于2,3-DPG在给定的氧张力下会降低氧合血红蛋白S的百分比，所以会增强镰状化。此外，2,3-DPG有直接作用。当在体外增加细胞内2,3-DPG的浓度时，在给定的氧饱和度下会有更大比例的细胞发生镰状化。相反，在2,3-DPG被人为降低的细胞中镰状化受到抑制。这些数据表明，2,3-DPG对镰状化的增强作用部分独立于其对氧亲和力的影响。
